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- Posts: 13
- Joined: Fri Dec 27, 2013 8:20 am
We are using liquid-liquid extraction method with extraction solvent ethyl acetate. We have preformed recovery testing by comparing area ratios of analyte and IS in IS post-spiked (IS post spiked after QC extraction) samples with pure analytical solution. We got 17.4% and 20.4% CV for analyte 1 and analyte 2.
All other tests (Pr and Acc, stability etc.) passed.
We set 15% acceptance criteria on %CV.
According to FDA, recovery should not be 100%, but it should be precise at each level.
Even if the recovery is not precise, because LLE is a technique with high variability, IS can deviate from extraction to extraction: do we need to have criteria on recovery CV, if we are using SIL IS which will compensate for any deviation during extraction?
Could you say how you are doing recovery test?
Thanks in advance